Staying in the loop

Intaqua pilot installation

Founded in 2001 and looking for further investors, Intaqua separates "gray water" - waste water from bathtubs, sinks, washing machines, etc. - from "black water" - waste water from toilets. Black water can be further separated into "brown water" and "yellow water" - no explanation needed there.

Gray water is treated on site and recycled as potable tap water. Black water is also treated on site - via an ultrafiltration membrane and repeated biological and chemical oxidation - then recycled as clear, odorless water for flushing toilets.

With the help of special worms, faeces and toilet paper are converted into humus. The nitrogen, phosphorus and magnesium in urine are separated out to form fertiliser.

The result is virtual "water independence," the company says: an attractive proposition as freshwater resources dwindle and water prices rise. No potable tap water is "wasted" in toilets, which gobble up about 30 per cent of household supplies. No faecal water winds up in the environment, where it could be a hazard to human health.

"What’s really new - the total breakthrough - is the black-water loop," said Ulrich Braun, a microbiologist from Freiburg who is Intaqua’s founder and chief. He said the idea came to him after a moment of indecision whose consequences literally stunk.

Pulling a trailer filled with train-toilet contents he'd collected for a biogas project, Braun saw the traffic light ahead of him turn yellow. He waited too long, then hit the brakes hard. In science, sometimes, misfortune and inspiration run over together.

Intaqua's technologies have been developed at Hamburg-Harburg Technical University under the direction of Ralf Otterpohl, who heads the Department of Municipal and Industrial Waste-Water Management there.

"For several months we’ve shown that the processes really work," Otterpohl said. "We built a pilot plant able to serve 20 people, fed it with waste water, and have gained experience running it. Now we’re developing a prototype that can go into serial production."

Braun said the prototype - designed for "a mid-sized hotel" - would be built in collaboration with the Baden-Württemberg company Nill-Tech in a container that can be hauled around for demonstration purposes. "We expect it to be ready to travel by the middle of next year," he said, adding: "We want to make this thing a big export success for Germany."

Interest in the company has been high, Braun said, since it was featured on German television earlier this year. He pointed to the arid states along the Persian Gulf, as well as America and Asia as promising potential markets.

Intaqua is aiming its technologies at hotels, hospitals, office buildings, industrial sites, highway rest stops, cruise ships, and settlements with no more than 5,000 inhabitants. Larger settlements, it says, would require wide, concrete sewer pipes at prohibitive costs. Existing buildings can be retrofitted with the necessary piping.

One selling point cited by Intaqua takes the sad state of current world affairs into account. The decentralised nature of the company's water-supply systems makes them less vulnerable to terrorist attacks, the company notes.